1. Field of the Invention
The present invention relates to agricultural implements, and, more particularly, to agricultural field tillage implements.
2. Description of the Related Art
It is not an uncommon sight to see a farm tractor pulling cultivating or planting implements along rural roads. Field cultivating implements such as harrows include, in addition to the actual soil working tools such as harrow tines or discs, a set of wheels which are deployed when moving an implement between storage locations and one or more work locations eliminating the need for a separate implement transporting trailer. This same set of wheels may be employed to engage the farm field surface and control the depth or penetration of the soil working tools into the earth. A fixed wheel location would probably result in tool and/or roadway damage. Thus, various schemes for retracting and extending the wheels relative to the implement have been suggested. These schemes allow full wheel extension when transporting the implement and a controllable limited extension when cultivating. The wheels allow the implement to more nearly follow field contours. These schemes have the additional advantage that the depth of working tool penetration into the soil may be controlled for preferred tillage.
The known wheel retracting techniques employ one or more lift cylinders typically located at or near the rear of the implement, with mechanical linkages from the cylinders to respective wheels. Their weight undesirably adds weight to the implement behind the wheel pivots detrimentally affecting tongue weight.
What is needed in the art is a simple, fully adjustable wheel retracting scheme which shifts the weight forward on the implement.